From Sintering Route to Cutting Response: Circular-Saw Granite Cutting with Microwave-Hybrid Sintered Diamond Segments

Balancing low segment wear with stable cutting forces remains a challenge in granite sawing. This work compares diamond-impregnated saw segments produced by microwave– hybrid sintering (MWHS) and hot pressing (HP) when cutting Rosa Porriño granite. Tests were performed under tap-water cooling (22 L min−1) while varying peripheral speed (20–40 m s−1), feed speed (22–38 mm s−1), and cutting depth (9–18 mm). Cutting forces were recorded during successive slots, and wear was quantified as mass loss per machined area (1.2–3.0 m2 per test). MWHS segments exhibited lower wear than HP segments, with reductions up to ~20%, consistent with improved diamond retention and reduced binder exposure to debris-driven abrasion. Under higher cutting severity, however, MWHS segments developed higher forces, indicating reduced grit renewal and progressive blunting, plausibly linked to stronger diamond–matrix bonding and the low-friability diamond grade used. In contrast, HP segments operated at lower forces but showed higher wear, consistent with greater surface renewal through controlled grit release. Tuning diamond friability and matrix compliance in MWHS is proposed to stabilize forces while preserving the wear advantage. Overall, MWHS is a viable route for granite cutting segments, but further optimization is required to achieve HP-equivalent behavior across the tested conditions.